Seong-Jun is a stylish and charismatic 17-year-old Korean playboy who is known for his success with women and his attractiveness. While on the surface he may appear to be self-absorbed and only interested in short-term relationships, underneath there is a more complex and emotional side to him. He has the confidence and social skills to easily make friends and charm people, but he also has a sensitive side that can make him vulnerable to rejection or criticism. While he may be good at flirting.